Thermosetting resin compositions comprising epoxy resins, adhesion promoters and curatives based on the combination of nitrogen compounds and transition metal complexes

ABSTRACT

This invention relates to thermosetting resin compositions useful as underfill sealants for mounting to a circuit board semiconductor device packages, which have a semiconductor chip on a carrier substrate. Reaction products of these compositions demonstrate improved adhesion after exposure to elevated temperature conditions, improved resistance to moisture absorption and improved resistance to stress cracking.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to thermosetting resin compositions usefulas underfill sealants for mounting to a circuit board semiconductorchips or semiconductor device packages, which have a semiconductor chipon a carrier substrate. Reaction products of these compositionsdemonstrate improved adhesion after exposure to elevated temperatureconditions, improved resistance to moisture absorption and improvedresistance to stress cracking.

[0003] 2. Brief Description of Related Technology

[0004] In recent years, the popularity of smaller-sized electronicappliances has made desirable size reduction of semiconductor devices.As a result, chip packages are becoming reduced in size to substantiallythat of the bare die themselves. Such smaller-sized chip packagesimprove the characteristics of the microelectronic device in which it isused, while retaining many beneficial operating features. This serves toprotect semiconductor bare chips, and increases their reliability anduseful life.

[0005] Ordinarily, chip assemblies are connected to electricalconductors on a circuit board by use of solder connection or the like.However, when the resulting chip/circuit board structure is subjected toconditions of thermal cycling, reliability becomes suspect due tofatigue of the solder connection between the circuit board and the chipassembly. Recent manufacturing advances provide a sealing resin (oftenreferred to as underfill sealant) in the space created by the mountingof a semiconductor device, such as a chip scale package (“CSP”)/ballgrid array (“BGA”)/land grid array (“LGA”) assembly or a flip chip(“FC”) assembly, onto a circuit board to relieve stresses caused bythermal cycling. Underfill sealants have been seen to improve heat shockproperties and enhance the reliability of such structures.

[0006] Of course, curable resin compositions generally are known.However, a perception to many end users of such resin compositions inmicroelectronics applications, such as underfill sealants, is theirinability to retain adhesion after exposure to temperatures oftenreached during the solder reflow cycle. That is, due to the differenceof the coefficients of thermal expansion of the components of thesemiconductor device/circuit board interface, stresses in the underfillsealant occur (as contrasted to stresses in the semiconductor deviceand/or circuit board, had an appropriate underfill sealant not beenused) during thermal cycling.

[0007] That is, thermosetting epoxy formulations when cured, aretypically rigid and relatively brittle polymers with high modulusvalues. As such, much of the stress caused during thermal cycling istransferred to the CSP, BGA, LGA or FC assembly instead of the circuitboard, resulting in cracking when the stresses become severe. Whilethere are many commercially available flexibilizing agents, such asrubbers, thermoplastics, and diluents, that one may include to theformulation to improve flexibility by providing low modulus values,moisture absorption by the cured reaction product ordinarily increasesas a result, often to an unacceptable degree.

[0008] Attempts at improving adhesion of such underfill sealants haveoften involved the inclusion of materials that would tend to decreasethe crosslink density of the cured sealant. While such a decreaseimproves flexibility and thus oftentimes adhesion, it also has resultedin the increase of moisture absorption. Moisture absorption of suchsealants is seen as a detriment to the overall function of themicroelectronic device due to the increased chance of corrosion, andtherefore the malfunctioning of the device.

[0009] UOP Corporation offers commercially under the tradename UNILINK aseries of aromatic secondary diamines, which are promoted as useful inmodifying the urea linkage in polyurethane and polyurea compositions. Itis reported that the modification permits a greater amount of thediamine to be incorporated into the formulation, thereby resulting in apolyurethane or polyurea having superior strength and load bearingperformance, as well as improved dimensional stability, as compared tofoams prepared without the diamine. These diamines are not believed tohave been promoted to date for use in epoxy-based formulations, such asones not based on anhydride curing, let alone for the purpose ofimproving adhesion after exposure to elevated temperature conditions andresistance to moisture absorption.

[0010] U.S. Pat. No. 5,503,936 (Blyakhman) describes and claims curablemodified epoxy resin compositions having an epoxy resin, a hardener orcuring agent and 2.5 to 12.5% by weight of a compound represented by

[0011] where E and T are C₅₋₁₂ alkyl, C₅₋₈ cycloalkyl, C₇₋₁₅phenylalkyl, or C₆₋₁₀ aryl, with or without substitution by one or twoC₁₋₄ groups. The hardeners or curing agents of the '936 patent aredescribed as aliphatic, aromatic or cycloaliphatic di- or polyamines,such as diethylenetriamine, N-aminoethylpiperazine,4,4′-diaminodicyclohexylmethane, 4,4′-diaminodiphenyl sulfone,diethyldiaminotoluene, dicyandiamide, or guanidine; polycarboxylic acidanhydrides, such as phthalic anhydride or trimellitic anhydride;catalytic curing agents such as tertiary amines, imidazoles or complexesof boron trifluoride; difunctional and multifunctional phenols; orphenol or cresol novolac resins.

[0012] In addition, in “High Performance No-Flow Underfills for Low-TestFlip Chip Applications: Material Characterization”, IEEE Transactions onComponents, Pack'g and Man'g Tech.—Part A, 21, 3, 450-58 (September1998), C. P. Wong et al. describes the use of cobalt acetylacetonate asa curing catalyst for underfill materials based on certain epoxy resinsand anhydrides. These curing catalysts are described as latent and arenoted as having no noticeable concentration dependent effect on thefinal properties of the cured samples. See also International PatentPublication No. WO 98/37134. In the context of epoxy/cyanate estercurable compositions, see also U.S. Pat. No. 5,969,036 (Dershem).

[0013] It would be desirable for an underfill sealant composition toprovide good adhesive properties, such as flexibility, while at leastmaintaining the current level of, if not improving the, resistanceagainst moisture absorption, while improving the stress crackingresistance of the cured product. With such physical properties of thecured product, CSP, BGA, LGA and/or FC assemblies should have improvedreliabilities, all else being equal of course.

SUMMARY OF THE INVENTION

[0014] The present invention is directed to thermosetting. resincompositions, whose reaction products demonstrate improved adhesion,improved resistance to moisture absorption, and improved stress crackingresistance. The compositions include an epoxy resin component; aadhesion promoter component including at least two secondary aminefunctional groups; and a curative based on the combination of anitrogen-containing compound and a transition metal complex.

[0015] In one microelectronic application, the inventive thermosettingresin compositions are useful as underfill sealant compositions, which(1) rapidly fill the underfill space in a semiconductor device, such asa FC assembly which includes a semiconductor chip mounted on a circuitboard, the underfill space between a semiconductor chip and a carriersubstrate of a CSP, and/or the underfill space between a CSP and acircuit board, (2) enables the semiconductor chip or device to besecurely connected to a circuit board by short-time heat curing and withgood productivity, (3) demonstrates excellent heat shock properties (orthermal cycle properties) and (4) demonstrates improved adhesion,resistance to moisture absorption, and resistance to stress cracking.

[0016] By using the thermosetting resin compositions of this invention,semiconductor devices, such as CSP, BGA or FC assemblies, may besecurely connected to a circuit board by short-time heat curing of thecomposition, with the resulting mounted structure (at least in part dueto the cured composition) demonstrating excellent heat shock properties(or thermal cycle properties). The cured adhesive retains its strengtheven after exposure to elevated temperature conditions, such as thosetemperatures reached during solder reflow cycles, and is not compromisedby the stresses experienced as a result of the differences ofcoefficients of thermal expansion between and among the components ofthe semiconductor device and/or circuit board to which the semiconductordevice is electrically attached. In addition, the cured adhesivedemonstrates improved adhesion, resistance to moisture absorption, andresistance to stress cracking, particularly at elevated temperatures,and even when cycled between temperature extremes.

[0017] The present invention also provides a mounting structure forsemiconductor devices. The mounting structure is constructed of asemiconductor device that includes a semiconductor chip mounted on acarrier substrate, and a circuit board to which the semiconductor deviceis electrically connected, with the space between the carrier substrateof the semiconductor device and the circuit board sealed with a reactionproduct of the inventive thermosetting resin composition.

[0018] In addition, the present invention provides a process forfabricating semiconductor devices. The process includes electricallyconnecting a semiconductor chip or semiconductor device, which includesa semiconductor chip mounted on a carrier substrate, to a circuit board,and infiltrating the inventive compositions into the space between thesemiconductor chip or carrier substrate of the semiconductor device andthe circuit board.

[0019] The compositions of this invention may also be used formicroelectronic applications beyond sealing underfill, such asencapsulation, glob top, overfills and the like, as well as otherapplications for thermosetting compositions in which improved adhesionand improved resistance to water absorption are desirable.

[0020] The benefits and advantages of the present invention will becomemore readily apparent after a reading of the “Detailed Description ofthe Invention” together with the figure.

BRIEF DESCRIPTION OF THE FIGURES

[0021]FIG. 1 depicts a cross-sectional view showing an example of amounted structure with which the thermosetting resin composition of thepresent invention is used as an underfill sealant.

[0022]FIG. 2 depicts a cross-sectional view showing another example of amounted structure with which the thermosetting resin composition of thepresent invention is used as an underfill sealant.

DETAILED DESCRIPTION OF THE INVENTION

[0023] As noted above, the thermosetting resin compositions which areuseful as underfill sealants between a semiconductor chip, or asemiconductor device, which includes a semiconductor chip mounted on acarrier substrate, and a circuit board to which the semiconductor deviceis electrically connected, include an epoxy resin component, a secondaryamine-based adhesion promoting component and a curative based on thecombination of a nitrogen containing compound and a transition metalcomplex. Reaction products of these compositions demonstrate improvedadhesion, improved resistance to moisture absorption, and improvedresistance to stress cracking.

[0024] Typically, the composition includes about 60 to about 95.8 weightpercent of the epoxy resin component, about 5 to about 30 weight percentof the secondary amine-based adhesion promoting component, and about 0.2to about 10 weight percent of the curative, of which about 80 to about98 weight percent is comprised of the nitrogen containing compound andabout 2 to about 20 weight percent is comprised of the transition metalcomplex.

[0025] The epoxy resin component of the present invention may includeany common epoxy resin, which may have at least one multifunctionalepoxy resin.

[0026] Examples of such epoxy resins include C₄-C₂₈ alkyl glycidylethers; C₂-C₂₈ alkyl- and alkenyl-glycidyl esters; C₁-C₂₈ alkyl-, mono-and poly-phenol glycidyl ethers; polyglycidyl ethers of pyrocatechol,resorcinol, hydroquinone, 4,4′-dihydroxydiphenyl methane (or bisphenolF, such as RE-404-S or RE-410-S available commercially from NipponKayuku, Japan), 4,4′-dihydroxy-3,3′-dimethyldiphenyl methane,4,4′-dihydroxydiphenyl dimethyl methane (or bisphenol A),4,4′-dihydroxydiphenyl methyl methane, 4,4′-dihydroxydiphenylcyclohexane, 4,4-dihydroxy-3,3′-dimethyldiphenyl propane,4,4′-dihydroxydiphenyl sulfone, and tris(4-hydroxyphyenyl)methane;polyglycidyl ethers of transition metal complex chlorination andbromination products of the above-mentioned diphenols; polyglycidylethers of novolacs; polyglycidyl ethers of diphenols obtained byesterifying ethers of diphenols obtained by esterifying salts of anaromatic hydrocarboxylic acid with a dihaloalkane or dihalogen dialkylether; polyglycidyl ethers of polyphenols obtained by condensing phenolsand long-chain halogen paraffins containing at least two halogen atoms;N,N′-diglycidyl-aniline;N,N′-dimethyl-N,N′-diglycidyl-4,4′-diaminodiphenyl methane;N,N,N′,N′-tetraglycidyl-4,4′-diaminodiphenyl methane;N,N′-diglycidyl-4-aminophenyl glycidyl ether;N,N,N′,N′-tetraglycidyl-1,3-propylene bis-4-aminobenzoate; phenolnovolac epoxy resin; cresol novolac epoxy resin; and combinationsthereof.

[0027] Among the commercially available epoxy resins suitable for useherein are polyglycidyl derivatives of phenolic compounds, such as thoseavailable under the tradenames EPON 828, EPON 1001, EPON 1009, and EPON1031, from Shell Chemical Co.; DER 331, DER 332, DER 334, and DER 542from Dow Chemical Co.; GY285 from Ciba Specialty Chemicals, Tarrytown,N.Y.; and BREN-S from Nippon Kayaku, Japan. Other suitable epoxy resinsinclude polyepoxides prepared from polyols and the like and polyglycidylderivatives of phenol-formaldehyde novolacs, the latter of which areavailable commercially under the tradenames DEN 431, DEN 438, and DEN439 from Dow Chemical Company. Cresol analogs are also availablecommercially ECN 1235, ECN 1273, and ECN 1299 from Ciba SpecialtyChemicals. SU-8 is a bisphenol A-type epoxy novolac available from ShellChemicals (formerly, Interez, Inc.). Polyglycidyl adducts of amines,aminoalcohols and polycarboxylic acids are also useful in thisinvention, commercially available resins of which include GLYAMINE 135,GLYAMINE 125, and GLYAMINE 115 from F.I.C. Corporation; ARALDITE MY-720,ARALDITE MY-721, ARALDITE 0500, and ARALDITE 0510 from Ciba SpecialtyChemicals and PGA-X and PGA-C from the Sherwin-Williams Co. And ofcourse combinations of the different epoxy resins are also desirable foruse herein.

[0028] As noted above, the epoxy resin component of the presentinvention may include any common epoxy resin, at least a portion ofwhich is a multifunctional epoxy resin. ordinarily, the multifunctionalepoxy resin should be included in amount within the range of about 20weight percent to about 100 weight percent of the epoxy resin component.

[0029] A monofunctional epoxy resin, if present, should ordinarily beused as a reactive diluent, or crosslink density modifier. In the eventsuch a monofunctional epoxy resin is included as a portion of the epoxyresin component, such resin should be employed in an amount of up toabout 20 weight percent, based on the total epoxy resin component.

[0030] In choosing epoxy resins for the epoxy resin component of thecompositions of the present invention, consideration should also begiven to viscosity and other properties thereof.

[0031] The secondary amine-based adhesion promoting component shouldhave at least two secondary amines available for reaction. For instance,the secondary amine-based adhesion promoting component may berepresented as within the following structure I:

[0032] where R and R¹ may be the same or different and may be selectedfrom C₁₋₁₂ alkyl, C₁₋₁₂ alkenyl, C₅₋₁₂ cyclo or bicycloalkyl, C₆₋₁₈aryl, and derivatives thereof, and ◯ may be selected from C₁₋₁₂alkylene, C₁₋₁₂ alkenylene, C₅₋₁₂ cyclo or bicycloalkylene, C₅₋₁₂ cycloor bicycloalkenylene, C₆₋₁₈ arylene, and derivatives thereof.

[0033] Within structure I are a variety of secondary amines that may beused herein, for instance, the aromatic secondary diamines representedby structures II-V below:

[0034] Structure II (UNILINK 4200) is N,N′-bis-(2-butyl)-p-methylenedianiline, structure III (UNILINK 7100) isN,N′-bis-4-(5-methyl-2-butyl)-p-phenylene diamine, structure IV (UNILINK4100) is N,N′-bis-4-(2-butyl)-p-phenylene diamine, and structure V(UNILINK 4102) is N,N′-bis-4-(2-methylpropyl)-o-phenylene diamine.

[0035] In addition, within structure I is structure VI below, which isN-2-pentyl-N′-phenyl-p-phenylene diamine, which may also be used.

[0036] This phenylene diamine is believed to be available from UniroyalChemical Co., under the tradename FLEXZONE 7L.

[0037] The secondary amine-based adhesion promoting component should beused in the inventive compositions in an amount within the range ofabout 5 to about 30 weight percent, with about 13 to about 20 weightpercent being particularly desirable, depending of course on theidentity of the chosen secondary amine-based adhesion promotingcomponent.

[0038] The curative includes a combination of nitrogen-containingcompounds, like amines, imidazoles, amides, and like, and combinationsthereof, and a transition metal complex.

[0039] Examples of the amine compounds polyamines and di- and tri-azacompounds, such as

[0040] 1,5-diazabicyclo[3.4.0]non-5-ene;

[0041] 1,8-diazabicyclo[5.4.0]undec-7-ene;

[0042] 1,5,7-triazabicyclo[4.4.0]dec-5-ene;

[0043] the bicyclo mono- and di-aza compounds:

[0044] quinuclidine;

[0045] 1,4-diazabicyclo[2.2.2]octane;

[0046] the aliphatic polyamines:

[0047] diethylenetriamine, triethylenetetraamine,diethylaminopropylamine;

[0048] the aromatic polyamines:

[0049] benzyl dimethylamine, m-xylenediamine, diaminodiphenylamine andquinoxaline; and

[0050] the alicyclic polyamines:

[0051] isophoronediamine and menthenediamine.

[0052] Of course, combinations of these amine compounds are alsodesirable for use in the compositions of the present invention.

[0053] Examples of imidazoles include imidazole and derivatives thereof,such as isoimidazole, imidazole, alkyl substituted imidazoles, such as2-ethyl-4-methylimidazole, 2,4-dimethylimidazole, butylimidazole,2-heptadecenyl-4-methylimidazole, 2-methylimidazole,2-undecenylimidazole, 1-vinyl-2-methylimidazole, 2-undecylimidazole,2-heptadecylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole,1-propyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole,1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole,1-cyanoethyl-2-phenylimidazole, 1-guanaminoethyl-2-methylimidazole andaddition products of an imidazole methylimidazole and addition productsof an imidazole and trimellitic acid, 2-n-heptadecyl-4-methylimidazoleand the like, generally where each alkyl substituent contains up toabout 17 carbon atoms and desirably up to about 6 carbon atoms, arylsubstituted imidazoles, such as phenylimidazole, benzylimidazole,2-methyl-4,5-diphenylimidazole, 2,3,5-triphenylimidazole,2-styrylimidazole, 1-(dodecyl benzyl)-2-methylimidazole,2-(2-hydroxyl-4-t-butylphenyl)-4,5-diphenylimidazole,2-(2-methoxyphenyl)-4,5-diphenylimidazole,2-(3-hydroxyphenyl)-4,5-diphenylimidazole,2-(p-dimethylaminophenyl)-4,5-diphenylimidazole,2-(2-hydroxyphenyl)-4,5-diphenylimidazole,di(4,5-diphenyl-2-imidazole)-benzene-1,4,2-naphthyl-4,5-diphenylimidazole, 1-benzyl-2-methylimidazole,2-p-methoxystyrylimidazole, and the like generally where each arylsubstituent contains up to about 10 carbon atoms and desirably up toabout 8 carbon atoms.

[0054] A particularly desirable imidazole for use herein is1-(2-cyanoethyl)-2-ethyl-4-methylimidazole, available commercially fromBorregaard Synthesis Inc., Newburyport, Mass. under the tradenameCURIMID CN

[0055] Of course, combinations of these imidazoles are also desirable asthe imidazole component of the latent hardener component of thecompositions of the present invention.

[0056] Examples of amide compounds include cyano-functionalized amides,such as dicyandiamide.

[0057] Of course, combinations of these various nitrogen containingcompounds are also desirable for use in the compositions of the presentinvention.

[0058] The transition metal complex may be chosen from a variety oforganometallic materials or metallocenes. Those materials of particularinterest herein may be represented by metallocenes within structure VII:

[0059] where R₁ and R₂ may be the same or different and may occur atleast once and up to as many four times on each ring in the event of afive-membered ring and up to as many as five times on each ring in theevent of a six-membered ring;

[0060] R₁ and R₂ may be selected from H; any straight- or branched-chainalkyl constituent having from 1 to about 8 carbon atoms, such as —CH₃,—CH₂CH₃, —CH₂CH₂CH₃, —CH (CH₃)₂, —C(CH₃)₃ or the like; acetyl; vinyl;allyl; hydroxyl; carboxyl; —(CH₂)_(n)—OH, where n may be an integer inthe range of 1 to about 8; —(CH₂)_(n)—COOR₃, where n may be an integerin the range of 1 to about 8 and R₃ may be any straight- orbranched-chain alkyl constituent having from 1 to about 8 carbon atoms;H; Li; Na; —(CH₂)_(n)—OR₄, wherein n may be an integer in the range of 1to about 8 and R₄ may be any straight- or branched-chain alkylconstituent having from 1 to about 8 carbon atoms; or (CH₂)_(n)N+(CH₃)₃X⁻, where n may be an integer in the range of 1 to about 8 and X may beCl⁻, Br⁻, I⁻, ClO₄ ⁻ or BF₄ ⁻;

[0061] Y₁ and Y₂ may not be present at all, but when at least one ispresent they may be the same or different and may be selected from H,Cl⁻, Br⁻, I⁻, cyano, methoxy, acetyl, hydroxy, nitro, trialkylamines,triaryamines, trialkylphosphines, triphenylamine, tosyl and the like;

[0062] A and A′ may be the same or different and may be C or N;

[0063] m and m′ may be the same or different and may be 1 or 2; and

[0064] M_(e) is Fe, Ti, Ru, Co, Ni, Cr, Cu, Mn, Pd, Ag, Rh, Pt, Zr, Hf,Nb, V, Mo and the like.

[0065] Of course, depending on valence state, the element represented byM_(e) may have additional ligands—Y₁ and Y₂—associated therewith beyondthe carbocyclic ligands depicted above (such as where M_(e) is Ti and Y₁and Y₂ are Cl⁻).

[0066] Alternatively, metallocene structure VII may be modified toinclude materials such as those within structure VIII below:

[0067] where R₁, R₂, Y₁, Y₂, A, A′, m, m′ and M_(e) are as definedabove.

[0068] A particularly desirable example of such a material is where R₁and R₂ are each H; Y₁ and Y₂ are each Cl; A and A′ are each N; m and m′are each 2 and M_(e) is Ru.

[0069] Within metallocene structure VII, well-suited metallocenematerials may be chosen from within metallocene structure IX:

[0070] where R₁, R₂ and M_(e) are as defined above.

[0071] Particularly well-suited metallocene materials from withinstructure I may be chosen where R₁, R₂, Y₁, Y₂, m and m′ are as definedabove, and M_(e) is chosen from Ti, Cr, Cu, Mn, Ag, Zr, Hf, Nb, V andMo.

[0072] Desirably, the metallocene is selected from ferrocenes (i.e.,where Me is Fe), such as ferrocene, vinyl ferrocenes, ferrocenederivatives, such as butyl ferrocenes or diarylphosphino metal-complexedferrocenes [e.g., 1,1-bis (diphenylphosphino) ferrocene-palladiumdichloride], titanocenes (i.e., where M_(e) is Ti), such asbis(η⁵-2,4-cyclopentadien-1-yl)-bis-[2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl]titanium which is available commercially from Ciba Specialty Chemicals,Tarrytown, N.Y. under the tradename “IRGACURE” 784DC, and derivativesand combinations thereof. A particularly desirable metallocene isferrocene.

[0073] And bis-alkylmetallocenes, for instance, bis-alkylferrocenes(such as diferrocenyl ethane, propanes, butanes and the like) are alsodesirable for use herein, particularly since about half of theequivalent weight of the material (as compared to a non-bis-metallocene)may be employed to obtain the sought-after results, all else beingunchanged. Of these materials, diferrocenyl ethane is particularlydesirable.

[0074] Of course, other materials are well-suited for useM_(e)[CW₃—CO—CH═C(O⁻)—CW′₃]₂, where M_(e) is as defined above, and W andW′ may be the same or different and may be selected from H, andhalogens, such as F and Cl. Examples of such materials include platinum(II) acetylacetonate (“PtACAC”), cobalt (II) acetylacetonate(“Co(II)ACAC”), cobalt (III) acetylacetonate (“Co(III)ACAC”), nickel(II) acetylacetonate (“NiACAC”), iron (II) acetylacetonate(“Fe(II)ACAC”), iron (III) acetylacetonate (“Fe(III)ACAC”), chromium(II) acetylacetonate (“Cr(II)ACAC”), chromium (III) acetylacetonate(“Cr(III)ACAC”), manganese (II) acetylacetonate (“Mn(II)ACAC”),manganese (III) acetylacetonate (“Mn(III)ACAC”) and copper (II)acetylacetonate (“CuACAC”).

[0075] Of course, combinations of these transition metal complexes mayalso be employed.

[0076] The curative should be used in the inventive compositions in anamount within the range of about 0.5 to about 10 weight percent, such asabout 1 to about 7 weight percent, with about 5 to about 7 weightpercent being particularly desirable. The nitrogen containing compoundshould form between about 80 to about 98 weight percent of the curative,with the balance being the transition metal complex.

[0077] Optionally, the thermosetting resin compositions of the presentinvention may contain other components, such as defoaming agents,leveling agents, adhesion promoters, dyes, pigments and fillers. Thefillers may be included to alter the physical properties of thecompositions, such as for rheology control, lowering moisture absorptionand/or structure building properties. Moreover, the compositions mayalso contain photopolymerization initiators, provided such materials donot adversely affect the desired properties of the composition.

[0078] The thermosetting resin compositions of the present invention maybe of the one-pack type, in which all the ingredients are mixedtogether, or of the two-pack type in which the epoxy resin component andlatent hardener component are stored separately and mixed together priorto use.

[0079] During application, the thermosetting resin compositionsaccording to the present invention penetrate and flow readily into thespace between the circuit board and the semiconductor device, or atleast show a reduction in viscosity under heated or use conditions thuspenetrating and flowing easily.

[0080] Generally, it is desirable to prepare the thermosetting resincompositions of this invention by selecting the types and proportions ofvarious components so that the gel time will be tailored to a specifiedperiod of time (such as 1 minute or 2 minutes) at a temperature of about150° C. In such case, the inventive compositions should show no orsubstantially no increase of viscosity after a period of time of aboutsix hours at room temperature. With such a pot life, the compositionsdemonstrate the ability to penetrate into the space between the circuitboard and the semiconductor device (e.g., of 100 to 200 μm) relativelyrapidly, and allow for a greater number of assemblies to be underfilledwithout observing a viscosity increase in the compositions, therebyrendering them less effective for application.

[0081] The inventive compositions may also include a filler component.The filler component acts to reduce the differences in the coefficientof thermal expansion between the circuit board or carrier substrate andthe silicon die, depending on the nature of the filler lower moisturepick up, and tends to increase viscosity. Appropriate filler componentsinclude silica (commercially available from Tatsumori), alumina(commercially available from Showa Denko), silica-coated aluminumnitride (commercially available from Dow Chemical), silver flake(commercially available from Degussa), zinc oxide (commerciallyavailable from Zinc Corporation of America), magnesium oxide(commercially available from Carborundum Corporation), boron nitride(commercially available from Carborundum Corporation), titanium oxide(commercially available from DuPont Corporation) and the like.

[0082] Generally, about 0.1 to about 300 weight percent of the fillercomponent may be used, with about 150 to 180 weight percent beingdesirable.

[0083] Reference to FIG. 1 shows a mounted structure (i.e., a flip chippackage) in which a thermosetting resin composition of the presentinvention has been applied and cured.

[0084] The flip chip package 4 is formed by connecting a semiconductorchip (a bare chip) 2 to a circuit board 1, and sealing the spacetherebetween suitably with a thermosetting resin composition 3. Thesemiconductor chip 2 is mounted at a predetermined position on thecircuit board 1 and electrodes 5 and 6 are electrically connected by asuitable electrical connection material 7 and 8, such as solder. Inorder to improve reliability, the space between the semiconductor chip 2and the circuit board 1 is sealed with a thermosetting resin composition3.

[0085] An alternative mounted structure, a CSP 20, is shown in FIG. 2.There, a semiconductor device 24 constructed of a semiconductor chip 22connected to a carrier substrate 21, the space therebetween suitablysealed with a thermosetting resin composition 23. The mounted structure20 is mounted at a predetermined position on the circuit board 21, andelectrodes 28 and 29 are electrically connected by a suitable electricalconnection material 26, such as solder. In order to improve reliability,the space between the mounted structure 20 and the circuit board 25 issealed with a thermosetting resin composition 27, and then cured. Thecured product of the thermosetting resin composition should completelyfill that space.

[0086] Carrier substrates may be constructed from ceramic substrates ofAl₂O₃, SiN₃ and mullite (Al₂O₃—SiO₂); substrates or tapes ofheat-resistant resins, such as polyamides; polyimides; bismaleimidetriazines; glass-reinforced epoxy; ABS and phenolic substrates which arealso used commonly as circuit boards; and the like. Any electricalconnection of the semiconductor chip to the carrier substrate may beused, such as connection by a high-melting solder or electrically (oranisotropically) conductive adhesive, wire bonding, and the like. Inorder to facilitate connections, the electrodes may be formed as bumps.

[0087] In a typical mounting process, solder ball (e.g., in cream orform) may be printed at appropriate positions on a carrier substrate andsuitably dried to expel solvent. A semiconductor chip may then mountedin conformity with the pattern on the carrier substrate. This carriersubstrate is then passed through a reflowing furnace to melt the solderto connect the semiconductor chip. Moreover, the solder may be appliedor formed on either the carrier substrate or the semiconductor chip.Alternatively, this connection may also be made by an electricallyconductive adhesive or an anisotropically conductive adhesive.

[0088] After the semiconductor chip is electrically connected to thecarrier substrate, the resulting structure is ordinarily subjected to acontinuity test or the like. After passing such test, the semiconductorchip may be fixed thereto with a thermosetting resin composition, asdescribed below. In this way, in the event of a failure, thesemiconductor chip may be removed before it is fixed to the carriersubstrate with the thermosetting resin composition.

[0089] Using a suitable application means, such as a dispenser, athermosetting resin composition in accordance with this invention isapplied to the periphery of the electrically-connected semiconductorchip. The composition penetrates by capillary action into the spacebetween the carrier substrate and the semiconductor chip.

[0090] The thermosetting resin composition is then thermally cured bythe application of heat. During the early stage of heating, thethermosetting resin composition shows a significant reduction inviscosity and hence an increase in fluidity, so that it more easilypenetrates into the space between the carrier substrate and thesemiconductor chip. Moreover, by preheating the carrier substrate, thethermosetting resin composition is allowed to penetrate fully into theentire space between the carrier substrate and the semiconductor chip.

[0091] Cured reaction products of the thermosetting resin compositionsof the present invention demonstrate excellent adhesive force, heatresistance and electric properties, and acceptable mechanicalproperties, such as flex-cracking resistance, chemical resistance,moisture resistance and the like, for the applications for which theyare used herein.

[0092] The amount of thermosetting resin composition applied should besuitably adjusted so as to fill almost completely the space between thecarrier substrate and the semiconductor chip, which amount of course mayvary depending on application.

[0093] Thermosetting resin compositions of the present invention mayordinarily be cured by heating to a temperature in the range of about120 to about 180° C. for a period of time of about 0.5 to 30 minutes.However, generally after application of the composition, an initial curetime of about 1 minute sets up the composition, and complete cure isobserved after about 15 minutes at a temperature of about 150° C. Thus,the composition of the present invention can be used in relativelymoderate temperatures and short-time curing conditions, and henceachieve very good productivity.

[0094] The present invention will be more readily appreciated withreference to the examples which follow.

EXAMPLES Example 1

[0095] In this example, compositions were prepared and evaluated forperformance in contrast with compositions prepared without the secondaryamine-based adhesion promoting component and with known flexiblizersthat promote adhesion, but do so while compromising resistance to waterabsorption.

[0096] More specifically, thermosetting resin compositions for underfillapplications were prepared by mixing together with stirring for a periodof time of about 10 minutes at room temperature in an open vessel anepoxy resin component including 100 weight percent of bisphenol F-typeepoxy resin, 20 weight percent of a secondary amine-based adhesionpromoting component [N,N′-bis-4-(2-methylpropyl)-p-phenylene diamine,available commercially from UOP Corporation, under the tradename UNILINK4100], and 3 weight percent of a curative(1-(2-cyanoethyl)-2-ethyl-4-methylimidazole, available commercially fromBorregaard Synthesis Inc., Newburyport, Mass. under the tradenameCURIMID CN).

[0097] After formation, the composition was transferred to a 10 mlsyringe made of non-reactive plastic, and the composition was dispensedthrough the 12G needle of the syringe into the junction between thecarrier substrate and semiconductor chip in a previously formedassembly. As such, the composition acts as an encapsulant for theelectrical solder connection.

[0098] After dispensing was complete, the assembly was transferred to anoven while the temperature was maintained at about 150° C. Thecomposition cured initially after about 1 minute, and thereafter curedcompletely after about 15 minutes at that temperature.

[0099] Separately, the composition was placed between a pair of lapshears and cured in the same way as the assembly above. The bound lapshears were removed from the oven and allowed to reach room temperature,at which point they were evaluated for bond strength. The curedcomposition was found to possess lap shear strength of about 1660 psi.

[0100] With respect to shelf-life stability, as noted above the gel timeof the composition was tailored to 1 minute at a temperature of 150° C.This composition was observed to experience no viscosity increase atroom temperature after a period of time of 6 hours; after a period oftime of about 15 hours the viscosity increase was observed to be about52%; and after a period of time of about 24 hours the viscosity increasewas observed to be about 88%.

[0101] Compositions A-D were prepared with the components listed in thenoted amounts, in parts per hundred (“phr”). (See Table 1.) As can beseen, Component A is an epoxy-based composition used as a control withno adhesion promoting component at all, while Components C and D areepoxy-based compositions in which an acrylonitrile rubber and apolyether flexibilizer, respectively, have been included as the adhesionpromoting component. TABLE 1 Component Composition (phr) Type Identity AB C D Epoxy Bisphenol F epoxy 100 100 100 100 Secondary Amine UNILINK4100 — 20 — — Adhesion Promoter Flexibilizer Acrylonitrile rubber — — 20— (ATBN) Flexibilizer Polyether flexibilizer — — — 20 (D2000) CurativeCURIMID CN 3 3 3 3

[0102] The performance of these compositions is set forth below in Table2. TABLE 2 Composition Physical Properties A B C D Flexibility: 20 milfilm bends around No Yes Yes Yes 0.25″ radius without cracking Immersionin boiling water for 24 hours: 2.4% 2.0% 3.0% 3.1% % weight gain

[0103] Composition A exhibits poor flexibility, i.e., adhesion afterexposure to elevated temperature conditions, and a 24-hour water boilweight gain of 2.4%. Composition B exhibits excellent flexibility [bywrapping a cured 20 mil (0.020 inch) film around a 0.25 inch radius bendwithout visual observation of cracking] and the 24-hour water boilweight gain drops to 2.0%.

[0104] Compositions C and D also exhibit excellent flexibility, as doesComposition B, however these compositions exhibit significantly highermoisture absorptions, under the same conditions.

Example 2

[0105] A composition prepared along the lines of composition B wasevaluated for stress crack resistance (composition P), and shown tocrack after cure and thermal cycling. In an effort to improve stresscrack resistance, a transition metal complex was included with thenitrogen containing compound as the curative. Tables 3a and 3b below setforth the components and the general ranges that one might use toprepare desirable compositions within the scope of the presentinvention. TABLE 3a Resin Component Component Weight % Epoxy   60-95.8Secondary Amine Adhesion Promoter  5-30 Curative (nitrogen containing0.2-10  composition and transition metal complex)

[0106] TABLE 3b Total Underfill Composition Component Weight % ResinComponent  25-100 Inorganic Filler  0-75 Silane Adhesion Promoter0.1-1   Flowability Agent 0-1 Pigment   0-1.0

[0107] Compositions E-O were prepared with the components listed in thenoted amounts. (See Table 4.) TABLE 4 Component Composition (Weight %)Type Identity E F G H I J K L M N O Epoxy RE-404-S 30.9 30.9 30.9 30.930.9 30.9 30.9 30.9 30.9 31.5 31.4 Secondary UNILINK 4.85 4.85 4.85 5.255.25 5.25 5.7 5.7 5.7 4.7 — Amine 4100 Adhesion UNILINK — — — — — — — —— — 4.7 Promoter 7100 Curative CURIMID CN 1.2 1.2 1.2 1.2 1.2 1.2 1.21.2 1.2 1.1 1.1 Co (III) ACAC 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.080.08 — 0.08 Inorganic SO-E5 62 63.5 65 62 63.5 65 62 63.5 65 62 62Filler Silane A-187 — — — — — — — — — 0.3 — Adhesion PromoterFlowability A-137 0.35 0.35 0.35 0.35 0.35 0.35 0.35 0.35 0.35 0.05 0.35Agent A-1100 0.57 0.57 0.57 0.57 0.57 0.57 0.57 0.57 0.57 — 0.3 PigmentCarbon Black 0.12 0.12 0.12 0.12 0.12 0.12 0.12 0.12 0.12 0.12 0.12

[0108] Compositions E-M and O were prepared in accordance with thisinvention, and demonstrated excellent performance. More specifically,resin castings made from these compositions were cured and cycled for 20second intervals from temperature extremes of boiling water to liquidnitrogen (a temperature of −181° C.); they performed very well.Composition N, without the transition metal complex, exhibited poorcrack resistance. (See below Table 5.) TABLE 5 Composition PhysicalProperty E F G H I J K L M N O Ave cycles to 6.2 6.6 4.8 3.9 4.5 2.8 5.13.5 3.3 1.2 2.6 initiate cracking

Example 3

[0109] The effect of the transition metal complex, in this case thecobalt complexes Co(II)ACAC and Co(III)ACAC, on the physical propertiesof cured reaction products was examined by preparing 1%-cobaltmaster-batch solutions in the epoxy resin, RE-404-S, and formulatingcompositions as shown below in Table 6. TABLE 6 Component Composition(grams) Type Identity P Q R S T Epoxy RE-404-S 8.8 5.8 6.8 5.8 6.8Secondary Amine UNILINK 4100 1 1 1 1 1 Adhesion Promoter Curative(nitrogen CURIMID CN 0.2 0.2 0.2 0.2 0.2 containing Co(II)ACAC (1%) — 32 — — compositions and Co(III)ACAC (1%) — — — 3 2 transition metalcomplex)

[0110] The performance of the compositions was determined on thick neatresin castings with embedded steel washers (to provide extra thermalexpansion stress), which were sensitive to cracking during coldexposure. Performance data are set forth below in Table 7. TABLE 7Physical Property: Composition Cracking P Q R S T After cure Yes No NoNo No Dry ice cycles* — 6 2 7 4

Example 4

[0111] Compositions U-Z were prepared with the following constituents inthe amounts noted below in Table 8. TABLE 8 Composition (phr) ComponentU V X Y Z RE-404-S 30 30 30 30 30 UNILINK 4100 5 5 5 — — CURIMID CN 1.2— 1.2 1.2 1.2 Co(III)ACAC 0.1 0.1 — — 0.1

[0112] These compositions were cast and cured by exposure to an elevatedtemperature of about 150° C. for a period of time of about 2 hours.Performance of the compositions was determined on thick neat resincastings with embedded ⅜″ steel washers to provide extra thermalexpansion stress.

[0113] As shown below in Table 9, the resin castings were cycled betweentemperature extremes to determine their ability to resist stresscracking. Each cycle consisted of a 20 second immersion into liquidnitrogen followed by immersion into boiling water for 20 seconds. TABLE9 Composition Physical Property U V X Y Z Cycles to initiate cracking 120 3 1 1

[0114] Composition V did not cure completely and cracked while it cooledto room temperature from its cure temperature is of 150° C. CompositionsY and Z were observed to be brittle.

Example 5

[0115] In this example, Compositions AA-AE were prepared with thefollowing components in the amounts noted in Table 10. TABLE 10Component Composition (Weight %) Type Identity AA AB AC AD AE EpoxyRE-404-S 30.9 30.84 30.82 30.84 30.84 Secondary Amine UNILINK 4100 4.854.85 4.85 4.85 4.85 Adhesion Promoter Curative Co (III) ACAC — — 0.080.06 0.06 Co (II) ACAC — 0.06 — — — CURIMID CN 1.2 1.2 1.2 1.2 1.2Inorganic Filler SO-E5 62 62 62 62 62 Flowability A-137 0.05 0.05 0.050.05 0.35 Agent KR55 0.30 0.30 0.30 0.30 — A-1100 0.57 0.57 0.57 0.570.57 Pigment Carbon Black 0.13 0.13 0.13 0.13 0.13

[0116] These compositions were cured at a temperature of about 150° C.Die-shear adhesion testing after pressure-cooker preconditioning wasthen performed on the cured reaction products by allowing the vessel toreach a temperature of about 121° C. under a pressure of about 2 atm,for a period of time of 16 hours. After reaching room temperature, a dieshear tester shearingly removed the die from the substrate. This testingprovides information as to adhesion retention after exposure to moistureat elevated temperature, data for which is shown in Table 11. The areaof adhesion loss (force per area shear strength) is measured in kg ave.A lower value is indicative of lower adhesion and translates intodecreased device reliability. TABLE 11 Composition (kg ave) PhysicalProperty AA AB AC AD AE 16-hr pressure 18.45 30.74 44.20 32.33 33.40cooker, die shear

[0117] Accordingly, it is seen that the presence of the secondaryamine-based adhesion promoting component, coupled with the combinationof the nitrogen containing compound with active hydrogen, such asCURIMID CN, and the transition metal complex, such as Co(III)ACAC, asthe curative in the inventive compositions has a dramatic affect inimproving the flexibility and adhesion after exposure to elevatedtemperature conditions, improving the resistance to water absorption,and improving the stress crack resistance of reaction products of theinventive compositions. As such, it is seen that the compositions of thepresent invention possess utility in commercial applications beyondunderfill sealants for microelectronic applications. Indeed, within therealm of microelectronic applications, the inventive compositions may beused as encapsulants, glob top, overfills, and the like. In addition,the inventive compositions may be used in any commercial applicationwhere flexible cured epoxy adhesives with low moisture absorptionproperties and high stress crack resistance are desired.

[0118] The present invention has been illustrated above, though its truespirit and scope is defined by the claims.

What is claimed is:
 1. A thermosetting resin composition, saidcomposition comprising: (a) an epoxy resin component; (b) an adhesionpromoter component having at least two secondary amine functionalgroups;. and (c) a curative based on the combination of anitrogen-containing compound and a transition metal complex.
 2. Thecomposition of claim 1, wherein reaction products thereof demonstrateimproved adhesion after exposure to elevated temperature conditions. 3.The composition of claim 1, wherein reaction products thereofdemonstrate improved resistance to moisture absorption.
 4. Thecomposition of claim 1, wherein reaction products thereof demonstrateimproved resistance to stress cracking.
 5. The composition of claim 1,capable of sealing underfilling between a semiconductor device and acircuit board to which said semiconductor device is electricallyconnected, or a semiconductor chip and a circuit board to which saidsemiconductor chip is electrically connected.
 6. The composition ofclaim 1, wherein said epoxy resin comprises at least one multifunctionalepoxy resin.
 7. The composition according to claim 1, wherein the epoxyresin component includes members selected from the group consisting ofC₆-C₂₈ alkyl glycidyl ethers; C₆-C₂₈ fatty acid glycidyl esters; C₆-C₂₈alkylphenol glycidyl ethers; polyglycidyl ethers of pyrocatechol,resorcinol, hydroquinone, 4,4′-dihydroxydiphenyl methane,4,4′-dihydroxy-3,3′-dimethyldiphenyl methane, 4,4′-dihydroxydiphenyldimethyl methane, 4,4′-dihydroxydiphenyl methyl methane,4,4′-dihydroxydiphenyl cyclohexane, 4,4′-dihydroxy-3,3′-dimethyldiphenylpropane, 4,4′-dihydroxydiphenyl sulfone, andtris(4-hydroxyphyenyl)methane; polyglycidyl ethers of the chlorinationand bromination products of the above-mentioned diphenols; polyglycidylethers of novolacs; polyglycidyl ethers of diphenols obtained byesterifying ethers of diphenols obtained by esterifying salts of anaromatic hydrocarboxylic acid with a dihaloalkane or dihalogen dialkylether; polyglycidyl ethers of polyphenols obtained by condensing phenolsand long-chain halogen paraffins containing at least two halogen atoms;N,N′-diglycidyl-aniline;N,N′-dimethyl-N,N′-diglycidyl-4,4′-diaminodiphenyl methane;N,N,N′,N′-tetraglycidyl-4,4′-diaminodiphenyl methane;N-diglycidyl-4-aminophenyl glycidyl ether;N,N,N′,N′-tetraglycidyl-1,3-propylene bis-4-aminobenzoate; bisphenol Aepoxy resin, bisphenol F epoxy resin, phenol novolac epoxy resin, cresolnovolac epoxy resin and combinations thereof.
 8. The compositionaccording to claim 1, wherein the adhesion promoter including at leasttwo secondary amine functional groups is within the following structureI:

wherein R and R¹ may be the same or different and may be selected fromC₁₋₁₂ alkyl, C₁₋₁₂ alkenyl, C₅₋₁₂ cyclo or bicycloalkyl, C₆₋₁₈ aryl, andderivatives thereof, and ◯ may be selected from C₁₋₁₂ alkylene, C₁₋₁₂alkenylene, C₅₋₁₂ cyclo or bicycloalkylene, C₅₋₁₂ cyclo orbicyclalkenylene, C₆₋₁₈ arylene and derivatives thereof.
 9. Thecomposition according to claim 1, wherein the adhesion promotercomponent including at least two secondary amine functional groups is amember selected from the group consisting of


10. The composition according to claim 1, wherein the adhesion promotercomponent including at least two secondary amine functional groups ispresent in an amount within the range of from 5 to about 30 weightpercent, based on the total composition.
 11. The composition accordingto claim 1, wherein the nitrogen containing compound is a memberselected from the group consisting of amines, imidazoles, amides, andcomposition thereof.
 12. The composition according to claim 11, whereinthe amines are selected from the group consisting of1,5-diazabicyclo[3.4.0]non-5-ene, 1,8-diazabicyclo[5.4.0]undec-7-ene,1,5,7-triazabicyclo[4.4.0]dec-5-ene, quinuclidine,1,4-diazabicyclo[2.2.2]octane, diethylenetriamine,triethylenetetraamine, diethylaminopropylamine, benzyl dimethylamine,m-xylenediamine, diaminodiphenylamine, quinoxaline, isophoronediamineand menthenediamine.
 13. The composition according to claim 11, whereinthe imidazoles are selected from the group consisting of imidazole,isoimidazole, 2-methyl imidazole, 2-ethyl-4-methylimidazole,2,4-dimethylimidazole, butylimidazole, 2-heptadecenyl-4-methylimidazole,2-undecenylimidazole, 1-vinyl-2-methylimidazole, 2-undecylimidazole,2-heptadecylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole,1-propyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole,1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole,1-cyanoethyl-2-phenylimidazole, 1-guanaminoethyl-2-methylimidazole andaddition products of an imidazole methylimidazole and addition productsof an imidazole and trimellitic acid, 2-n-heptadecyl-4-methylimidazole,phenylimidazol, benzylimidazole, 2-methyl-4,5-diphenylimidazole,2,3,5-triphenylimidazole, 2-styrylimidazole, 1-(dodecylbenzyl)-2-methylimidazole,2-(2-hydroxyl-4-t-butylphenyl)-4,5-diphenylimidazole,2-(2-methoxyphenyl)-4,5-diphenylimidazole,2-(3-hydroxyphenyl)-4,5-diphenylimidazole,2-(p-dimethyl-aminophenyl)-4,5-diphenylimidazole,2-(2-hydroxyphenyl)-4,5-diphenylimidazole,di(4,5-diphenyl-2-imidazole)-benzene-1,4,2-napthyl-4,5-diphenylimidazole, 1-benzyl-2-methylimidazole,2-p-methoxystyrylimidazole, and combinations thereof.
 14. Thecomposition according to claim 11, wherein the imidazole is1-(2-cyanoethyl)-2-ethyl-4-methylimidazole.
 15. The compositionaccording to claim 1, wherein the transition metal complex is a memberselected from the group consisting of

wherein R₁ and R₂ may be the same or different and may occur at leastonce and up to as many four times on each ring in the event of afive-membered ring and up to as many as five times on each ring in theevent of a six-membered ring; R₁ and R₂ may be selected from H; anystraight- or branched-chain alkyl constituent having from 1 to about 8carbon atoms, such as —CH₃, —CH₂CH₃, —CH₂CH₂CH₃, —CH(CH₃)₂, —C(CH₃)₃ orthe like; acetyl; vinyl; allyl; hydroxyl; carboxyl; —(CH₂)n—OH, whereinn may be an integer in the range of 1 to about 8; —(CH₂)_(n)—COOR₃,wherein n may be an integer in the range of 1 to about 8 and R₃ may beany straight- or branched-chain alkyl constituent having from 1 to about8 carbon atoms; H; Li; Na; —(CH₂)_(n)—OR₄, wherein n may be an integerin the range of 1 to about 8 and R₄ may be any straight- orbranched-chain alkyl constituent having from 1 to about 8 carbon atoms;or —(CH₂)_(n)N+(CH₃)₃ X⁻, where n may be an integer in the range of 1 toabout 8 and X may be Cl⁻, Br⁻, I⁻, ClO₄ ⁻ or BF₄ ⁻; Y₁ and Y₂ may not bepresent at all, but when at least one is present they may be the same ordifferent and may be selected from H, Cl⁻, Br⁻, I⁻, cyano, methoxy,acetyl, hydroxy, nitro, trialkylamines, triaryamines, trialkylphospines,triphenylamine, tosyl and the like; A and A′ may be the same ordifferent and may be C or N; m and m′ may be the same or different andmay be 1 or 2; and M_(e) is Fe, Ti, Ru, Co, Ni, Cr, Cu, Mn, Pd, Ag, Rh,Pt, Zr, Hf, Nb, V, and Mo;

wherein R₁, R₂, Y₁, Y₂, A, A′, m, m′ and M_(e) are as defined above;

wherein R₁, R₂ and M_(e) are as defined above; andM_(e)[CW₃—CO—CH═C(O⁻)—CW′₃]₂, wherein M_(e) is as defined above, and Wand W′ may be the same or different and may be selected from H, andhalogens.
 16. The. composition according to claim 1, wherein thetransition metal complex is a member selected from the group consistingof platinum (II) acetylacetonate; cobalt (II) acetylacetonate; cobalt(III) acetylacetonate; nickel (II) acetylacetonate; copper (II)acetylacetonate; iron (II) acetylacetonate; iron (III) acetylacetonate:chromium (II) acetylacetonate; chromium (III) acetylacetonate; manganese(II) acetylacetonate; manganese (III) acetylacetonate; copper (II)acetylacetonate; and combinations thereof.
 17. The composition accordingto claim 1, wherein the transition metal complex is a member selectedfrom the group consisting of cobalt (II) acetylacetonate; cobalt (III)acetylacetonate; and combinations thereof.
 18. The composition accordingto claim 1, wherein the curative is present in an amount within therange of 0.5 to about 10 weight percent.
 19. Reaction products accordingto claim
 1. 20. A mounting structure for semiconductor devices,comprising: a semiconductor device comprising a semiconductor chipmounted on a carrier substrate, and a circuit board to which saidsemiconductor device is electrically connected, wherein the spacebetween the carrier substrate of said semiconductor device and saidcircuit board is sealed with a reaction product of a thermosetting resincomposition according to claim
 1. 21. A process for fabricatingsemiconductor devices, said process comprising the steps of:electrically connecting a semiconductor chip, or a semiconductor devicecomprising a semiconductor chip mounted on a carrier substrate, to acircuit board; and infiltrating a thermosetting resin compositionaccording to claim 1 into the space between the semiconductor chip, orthe carrier substrate of said semiconductor device, and said circuitboard.